On 7/13/2026 1:32 AM, Daniel P. Berrangé wrote:
> On Fri, Jul 10, 2026 at 11:20:37AM -0700, Pierrick Bouvier wrote:
>> On 7/10/2026 4:52 AM, Daniel P. Berrangé wrote:
>>> On Fri, Jul 10, 2026 at 12:47:28PM +0100, Alex Bennée wrote:
>>>> Daniel P. Berrangé <[email protected]> writes:
>>>>
>>>> (added Edgar for Microblaze)
>>>>
>>>>> On Thu, Jul 09, 2026 at 09:24:12AM -0700, Pierrick Bouvier wrote:
>>>>>> On 7/9/2026 9:13 AM, Daniel P. Berrangé wrote:
>>>>>>> On Thu, Jul 09, 2026 at 07:48:14AM -0700, Pierrick Bouvier wrote:
>>>>>>>> On 2/10/2026 8:35 AM, Daniel P. Berrangé wrote:
>>>>>>>>> When a developer's environment is already within a podman container it
>>>>>>>>> is not possible to use 'podman' again to create containers. It will
>>>>>>>>> usually result in wierd errors such as:
>>>>>>>>>
>>>>>>>>>   Error: fatal error, invalid internal status, unable to create a new 
>>>>>>>>> pause process: cannot re-exec process to join the existing user 
>>>>>>>>> namespace. Try running "podman system migrate" and if that doesn't 
>>>>>>>>> work reboot to recover
>>>>>>>>>
>>>>>>>>> Podman offers the ability to talk to a daemon outside the container,
>>>>>>>>> however, which could be leveraged by QEMU.
>>>>>>>>>
>>>> <snip>
>>>>>>>> Taking a look at why tcg tests are slow to compile, I reached this
>>>>>>>> commit. It seems like that calling 'podman info' is 5 to 10 times 
>>>>>>>> slower
>>>>>>>> than calling 'podman version'.
>>>>>>>> Thus, a container run now takes +1s when it was 0.2 before.
>>>>>>>
>>>>>>> Hmmm, but we call 'docker.py probe' in configure and cache the result,
>>>>>>> so that probe should only be done once.  0.2 vs 1s is just noise in
>>>>>>> the context of configure.
>>>>>>>
>>>>>>> That you're seeing any negative effects suggests that we've got
>>>>>>> something not using the cached probe result, which we should fix.
>>>>>>>
>>>>>>
>>>>>> Not really, docker.py --engine X still calls X info.
>>>>>>
>>>>>> https://gitlab.com/qemu-project/qemu/-/blob/master/tests/docker/docker.py#L675
>>>>>> https://gitlab.com/qemu-project/qemu/-/blob/master/tests/docker/docker.py#L78
>>>>>>
>>>>>> Maybe the fix is to remove the check if user specified an explicit
>>>>>> engine. But in this case, there is a problem with podman-remote not
>>>>>> being detected anymore.
>>>>>>
>>>>>> We can fix this by introducing engine=podman-remote, and skip the check
>>>>>> if engine is explicitly set.
>>>>>> What do you think?
>>>>>
>>>>> Urgh, so i see now we have two code paths / make variables
>>>>>
>>>>>   RUNC=podman --remote
>>>>>   CONTAINER_ENGINE=auto
>>>>>
>>>>> Sometimes we'll invoke docker.py --engine $(CONTAINER_ENGINE)
>>>>> and sometimes we'll directly invoke $(RUNC).
>>>>
>>>> Yeah that could do with cleaning up. I suspect the only places we
>>>> actually still need the script is where we are doing binfmt_misc enabled
>>>> containers unless there is a way to emulate the copying of qemu into the
>>>> container with a plain call? Maybe all the systems now have the
>>>> persistent flags which would skip this.
>>>
>>> Yeah, I'd be inclined to say this is a job for the distros to have
>>> qemu-user integration, and simplify our life. THe docker.py script
>>> always confuses me.  We could choose podman vs podman --remote vs
>>> docker simply in the meson.build file, as we do for other dev env
>>> choices.
>>>
>>>> The toolchain case could be skipped if we could find hosted compilers
>>>> for microblaze. However I do see we have a patch in there.
>>>>
>>>>>
>>>>> The result of "probe" cannot be fed back in to "--engine" which
>>>>> is a bit of a mess. I think the "engine" concept should not be
>>>>> exposed on the cli, and instead have a "--runc" arg which takes
>>>>> the full arg(s), since we need probe to report the runc args
>>>>> for other reasons.
>>>>>
>>>>> With regards,
>>>>> Daniel
>>>>
>>>> -- 
>>>> Alex Bennée
>>>> Virtualisation Tech Lead @ Linaro
>>>>
>>>
>>> With regards,
>>> Daniel
>>
>> Is it me or did we incredibly derailed from original issue which was:
>> "It was fast to query which container engine is available, and now it's
>> 5-10 times slower to accommodate toolbox workflow where podman is
>> available but not really available?"
>> I agree it's sad to have several ways to set container engine, but it's
>> absolutely not related to the current issue.
> 
> It is relevant because that difference in speed is not something that
> should be noticable unless something is repeatedly probing over & over
> again which should not be done.
> 
>> Daniel, since you introduced the slow check path with podman info for
>> your personal need, I would appreciate if it's something you could fix also.
> 
> I'll looking into the missing caching.
>

Thanks!

> With regards,
> Daniel

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